Answer:
<em>Earth's gravity pulls air as close to the surface as possible. ... As altitude increases, the amount of gas molecules in the air decreases—the air becomes less dense than air nearer to sea level. This is what meteorologists and mountaineers mean by "thin air." Thin air exerts less pressure than air at a lower altitude.</em>
Answer:
critical angle = 64.79°
ray will not penetrate into the water
Explanation:
given details
refractive index of oil n1 = 1.47
refractive index of water n2= 1.33
incident angle = 71.4 °

= sin^{-1}(\frac{1.33}{1.47}
critical angle = 64.79°
incident angle > critical angle = reflection
incident angle < critical angle = refraction
In this case, 71.4 > 64.79 therefore it will undergo total internal reflection
therefore ray will not penetrate into the water
F=mxa
(25-2.6)=7 X a
22.4\7=a
a =3.2 metres per second squared